Fueling watercraft commonly results in a spillage of fuel that can harm marine life, generate a risk of fire, and damage the watercraft. For example, because fuel vapors are heavier than air they can rapidly spread into compartments of the watercraft. These vapors may be ignited upon reaching open flames or by starting the engine(s) or operating an electrical switch. In addition, a sheen of fuel sometimes seen on surface water near watercraft is a contaminant to people in or using the water and has a damaging impact on marine life. For these reasons, such spillage may result in stiff fines assessed to an operator.
The causes of spillage are many. By way of example, if the tank is overfilled, fuel may spill out of a fill tube connected to the tank or escape from a vent tube that provides venting for the tank. In addition, sudden movement of the watercraft may cause spillage, such as movement generated by a wave from a passing watercraft or a passenger jumping between the watercraft and a dock. Thus, fueling a watercraft is more challenging than fueling a still vehicle on land.
Various devices and methods have been proposed to prevent spillage. For example, the operator may purposefully underfill the fuel tank, e.g., pumping only 25 gallons of fuel knowing the watercraft has a 30-gallon tank. Unfortunately, this may result in reduced range. As another example, the operator may wedge a rag between the nozzle and a fuel port. However, this may not only leave the operator with the task of properly disposing of a contaminated rag, but may also prevent the fuel vapors from properly escaping. Yet another example is the fuel overflow prevention device disclosed in U.S. Pat. No. 5,894,809 to Grigaitis, which discloses a reservoir interposed between a fuel tank vent tube and an air vent port. The reservoir collects overflowing fuel from the fuel tank and returns it to the fuel tank. However, Grigaitis is unable to capture fuel exiting from a top of the fill tube, such as back splash. In addition, fuel may actually exit Grigaitis' air vent port before the operator is aware that the tank is full.